The Tech Bench

292 Radio Shop / FireCommunications Network

Sunday, March 22, 2009

RF Amplifiers

Oldtimer asks the question: "I have saw alot of explanation about having a low deadkey for driving an amp."

swing: butchering a transceivers' transmitter section to produce a double sideband signal with suppressed carrier so that you can use it with THE WRONG TYPE OF AMPLIFIER. the unusually low carrier in combination with the wildly excessive modulated power output levels are required to overcome the reverse cutoff biasing of class c amplifiers. these modifications are completely unnecessary when the correct amplifier is used with these transceivers.

class c amplifiers such as AmPower, Davemade, Destroyer, Fatboy, Gator & XForce, etc. are not designed to be used with am/ssb transceivers and this is one of the reasons why they're not. a class c amplifier is incapable of faithfully reproducing either the original input signal or maintaining the proper peak-to-carrier symmetry for am transmission. these parameters can only be achieved by a LINEAR AMPLIFIER, not a class c switch.

either use an amplifier with the correct forward bias for am/ssb applications or keep buying class c switches and continue butchering your transmitters with "swing kits" and other bullshit modifications to adapt them to amplifiers (switches) they're not designed to be used with.

Friday, January 16, 2009

Free Download

I receive many calls and emails from hobbyists in regard to the proper construction and operation of radio antennas in a wide range of services, from LF all the way to UHF. In an effort to assist in the understanding of the principles of radio antenna engineering i have added a link to my website where like minded individuals can download "Radio Antenna Engineering" by: Edmund A. LaPort. Visit the site and download your FREE copy of this helpfile/e-book today!

Sunday, March 11, 2007

Daylight Savings Time

if you're using an older version of windows as in the "98" flavors you might be looking for a way to get your machine up to speed with regard to the new Daylight Savings Time settings. you can download Windows Time Zone Editor and patch your older Win 98/SE/ME Operating System so you can get back to it!

Monday, October 31, 2005

Conditions, Solar Activity

if the current solar cycle is something you have reason to track then you'll want to check out the Solar Environment Panel here at: www.firecommunications.com/solar.shtml :if there's something you can't find there please email the webmaster. this is our bookmark link-of-the-month for November. the link is included in the appropriate section for your convenience.

Friday, October 28, 2005

Customer Appreciation Day

they're doing it again this year at R&L Electronics in Hamilton, Ohio. last years attendees included Alinco, Ameritron, Hygain, Icom, MFJ, Mirage, Vectronics and Yaesu. this year look for Comet and Garmin to show up. special pricing and prizes will be included. December 10, 2005 10am - 4pm.

CB Radio Mod Wiki

CB Candy Electronics

went looking for some hard-to-find parts the other day and discovered that the website had been suspended, heard another rumor that the money had run out. glad to see it was only a temporary thing. http://ctrlcom.com/charley3/